Magnetic door latch



Feb. 14, 1961 E. w. WEAVER MAGNETIC DOOR LATCH Filed Sept. 28, 1959 INVENTOR far/ 30. ZUuw'er 4 w 0 3 H 2 3 f G 3 m II. 2 a F 6 7 2 2 2 8 g m w 2 a A. J A /l l :2 v a m o 4 w a x!! I I ll 1 I I K W m V l w m w ATTORNEY United States Patent 2,911,789 mcsrnc it 'A'rcir w. weaveisiilhers, 011i asst .2 y ufacturmg Company, Stmfli'ers, Ohio, a corporation This invention relates to a door latch and more particularly to a door latch in which a permanent magnet is used as a primary latch means.

The principal object of the invention is the provision of a magnetic door latch incorporating a mechanical latching structure.

A further object of the invention is the provision of a magnetic door latch by which a storm door, for example, may be held in closed position in a frame by the operation of a permanent magnet.

A further object of the invention is the provision of a door latch incorporating a permanent magnet for holding the door in closed position and a mechanical latch for locking the door in closed position.

A still further object of the invention is the provision of a latch incorporating a movable latch bar and a permanent magnet for holding the latch bar in latched position.

A still further object of the invention is the provision of a simple and eflicient door latch device utilizing magnetic attraction for holding the door and a mechanical latch in desired position.

The latch for a storm door or the like disclosed herein comprises an improvement in the art relating to simple relatively low cost latches used for storm door hardware and which latches require means for holding the storm door in closed position as well as means for securing the storm door against accidental or deliberate opening.

Heretofore storm door latches have comprised keeper plates and latch bars arranged to be actuated manually and spring loaded so that mechanical engagement of the latch bar with the keeper plate results when the latch is closed. Such devices are notoriously short lived and are frequently broken due to slamming of the door so equipped.

The present invention provides a structure which may be readily attached to metal or wood storm doors and frames and which. utilizes a keeper plate and a permanent magnet for holding the storm door in closed position. The invention also provides a manually movable latch bar positioned on the keeper plate and engageable in an opening in the magnet mounting structure on the door frame so that it will be held in latched position by magnetic attraction.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being the intention to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a perspective view of the storm door latch.

Figure 2 is a vertical section on line 2-2 of Figure 1.

2,971,789 Patented Feb. 14, 1961 i 3 is a horizontal section on line 3-3'of Figure -1.

A, By referring to the drawings and Figures 1 and 3 in particular it will be seen that portions of a storm door frame 10,and a storm door 11 are illustrated with a housing 12 having out-turned apertured flanges 13 'se- .curedto the door frame 10 by fasteners 14. The housing 12 partially encloses a flanged plate 15, the flange 16 of which forms an end closure in the housing 12.

, 13y referring to Figure 3 it will be seen that a permanent magnet1 7 is positioned between a pair of magnetic jmat plates 18 and 18A and that the magnetic mat plates 18 and 18A, the magnet 17 and the flanged plate 15 are secured to the housinglZ by a rivet 19 positioned therethrough. The magnetic mat plate 18A has a slot 20 therein in a forwardly projecting end portion thereof and it will be observed that a similar forwardly projecting portion is formed on the magnetic mat plate 18 so that the pair of magnetic mat plates 18 and 18A extend beyond the housing 12 and the magnet 17 and thus form the poles of the magnet.

A keeper plate 21 apertured adjacent its ends, is secured by fasteners 22 to the storm door 11. The keeper plate 21 has a sidewardly extending raised portion 23 which is thereby offset sidewardly and outwardly with respect to the plane of the plate 21 and is thus in a position to mount a flanged guide plate 24 which is preferably formed of plastic such as nylon and a latch bar 25 which is slotted longitudinally as at 26 so that it can be retained in a longitudinally movable manner by a rivet 27. A plastic washer 28 is positioned between the head of the rivet 27 and the latch bar 25 so that the latch bar 25 is capable of being moved longitudinally so that one end thereof will engage the opening 20 in the magnetic mat plate 18A heretofore referred to. The opposite end of the latch bar 25 is out-turned as at 29 and provided with a plastic knob 30 so that it can be conveniently moved thereby.

It will thus be seen that the permanent magnet 17 which is preferably of the Alnico type performs two functions in the storm door latch herein disclosed. The first and primary function of the magnet being the retention of the keeper plate 21 on the door 11 which holds the door firmly in position against the magnet holding structure mounted on the door frame 10. Secondly, the magnet 17 secures the latch bar 25 in latched position in the opening 20 in the magnetic mat plate 18A and thereby prevents the latch bar from accidentally moving to unlatehed position. The plastic guide 24 and washer 28 hold the latch bar 25 with suflicient frictional engagement to prevent the latch bar from moving toward the magnet 17 when it is in unlatched position.

It will occur to those skilled in the art that the keeper plate 21 and the latch bar 25 must be made of ferrous metal so that they can be retained by the magnetic action of the permanent magnet 17. The magnetic mat plates 18 and 18A are also formed of ferrous metal. It will thus be seen that a simple and eflicient latch for a storm door or the like has been disclosed and which latch meets the several objects of the invention. Having thus described my invention what I claim is:

l. A magnetic latch for a storm door and comprising a permanent magnet, a housing for said magnet, said I gaging formation on said magnet for mechanically engagwith end portions of said plates extending beyond said housing, and a keeper plate adapted to be attached to said stormdoor at a right angle to said magnetic mat plate being formed of ferrous metal, a latch bar slidably mounted on said keeper plate at one side of said magnet and magnetic mat plates so as to be engageable in an opening in one of'said magnetic mat plates whereby said 15 permanent magnet holds-said latch bar in latched posi' 'tion in said opening in said magnetic mat plate,

3. The magnetic storm door latch set forth in claim 2 ing and magnetically securing said keeper bar when enar andwhereinthekeeper plate, has. assidewardly extending otfset section spaced with respect to said storm door and 'ivherein said keeper bar is" slidably mounted on said ofiset section.

4. The storm door latch set forth in claim 2 and wherein the keeper platehasa sidewardly extending offset section, a plastic guide-positioned on said offset section, a rivet secured to said oflset section'and positioned vthrough said plastic guide and through an elongated lates and in a position to be engageable with said mag- 10 opening'in said keeperlbar. hetic mat plates, said magnetic'mat plates and keeper.

References Cited in the file of this patent UNITED STATES 'PATENTS' 1,230,740 McCra'cken June 19, 1917 1,428,367 Forlander Sept. 5, 1922 1,566,847 Firmbach Dec. 22, 1925 

